1. Field of the Invention
The present invention relates to a sheet collection apparatus for collecting sheets discharged from an image formation apparatus such as a copier and various types of printers, and more particularly, to a sheet collection apparatus capable of increasing a collection amount of discharged sheets.
2. Description of the Related Art
Generally, it is known widely to collect sheets after performing sheet folding processing and/or sheet binding processing on sheets carried out of an image formation apparatus or without performing such processing.
In addition, in recent years, it has been required to downsize the image formation apparatus and sheet collection apparatus including sheet processing attached to the image formation apparatus. In order to respond to the requirement, an apparatus is proposed where the sheet collection apparatus is disposed above the image formation apparatus after processing sheets.
For example, in Japanese Patent Gazette No. 5763898, an image formation section and space above the section is provided, a reading section for reading an original document is disposed above the space, a sheet collection apparatus including a sheet post-processing section for binding sheets is disposed in the space, and it is thereby intended to reduce the size of the entire image formation apparatus.
The sheet collection apparatus disposed in the space performs post-processing such as punch processing and binding processing on sheets discharged from a discharge roller of the image formation section, and then, stores processed sheets on a collection tray.
For the collection tray, as shown in FIG. 9 of Japanese Patent Gazette No. 5763898, since the sheet collection apparatus is disposed in the above-mentioned space, as compared with the conventional case of attaching the sheet collection apparatus to the side portion of the image formation apparatus, the protruding amount is small, and the apparatus is downsized. The collection tray is capable of storing sheets without undergoing punching or binding.
Further, also in Japanese Patent Application Publication No. 2014-106294, as shown in FIGS. 5 and 6 of the document, the sheet collection apparatus having a sheet discharge tray to perform post-processing is disposed in space between the image formation section and the original document reading section. Also in this apparatus, since all portions for performing binding processing are positioned above the image formation section, a portion protruding to the side of the apparatus is small, and downsizing is attained.
In sheet storage apparatuses shown in the above-mentioned Japanese Patent Gazette No. 5763898 and Japanese Patent Application Publication No. 2014-106294, since a discharge unit that is a sheet processing section is installed above the image formation section, an up-and-down range of the collection tray (sheet discharge tray) is limited to a range above the image formation section positioned to the side of the sheet processing section, and generally, a collection amount is limited to above 500 sheets to 1500 sheets. Accordingly, in order to increase a collection amount of the collection tray as required recently, it is necessary to replace with the sheet collection apparatus having the sheet processing section in the side portion of the image formation apparatus, which has conventionally existed.
However, it imposes significant loads economically and ought to be abandoned replacing with the entire apparatus so as to increase the collection amount on the collection tray by about 500 sheets to 1000 sheets.